Abstract P304: Association of Epigenetic Age Acceleration With Cognition in the Bogalusa Heart Study

Background: Despite known associations of epigenetic age acceleration (EAA), or increased DNA methylation (DNAm)-based age relative to chronological age, with Alzheimer’s disease, few studies have investigated the relation of EAA with midlife cognitive function. We examined cross-sectional associations of EAA with cognition among the 1,252 middle-aged participants of the Bogalusa Heart Study 2013-2016 study visit. Methods: Whole-blood DNA methylation data was generated using the Illumina HumanMethylation450 BeadChip. Four EAA measures, including extrinsic EAA (EEAA), intrinsic EAA (IEAA), PhenoAA and GrimAA, were derived from the methylation data. Cognitive function was assessed by a standard battery of eight neurocognitive tests covering five cognition domains, and a global cognition score was calculated. Associations of EAA measures with cognitive function were assessed by 3 multivariable models sequentially adding (i) demographics (age, sex, race, education) and vocabulary; (ii) lifestyle behaviors (smoking, alcohol drinking, and depression), and (iii) clinical measures (blood pressure, lipids, body mass index, glycated hemoglobin, medication, and white blood cell count. Results: After Bonferroni correction (α=1.39E-3), PhenoAA and GrimAA were significantly associated with decreased processing speed (lower Digit coding test score) and decreased working memory (higher trail making test A score). GrimAA was also associated with lower global cognition score ( Table ). EEAA was associated with decreased processing speed (lower Digit coding test). After adjusting for lifestyle and clinical measures, such associations were slightly attenuated but remained at least nominally significant. IEAA was not associated with any cognitive test results. Conclusions: EAA measured by PhenoAA, GrimAA, and EEAA were significantly associated with decreased processing speed, working memory, and/or global cognition. The associations were independent of known cognitive decline risk factors.